The present invention relates to a spray of an inhaler.
In general, sprays of inhalers or the like include a spray feeding a liquid medicine from a storage part such as a liquid medicine tank to a spray part formed by the vibrating surface of an oscillator and atomizing the liquid medicine. This type of spray is provided with a function enabling the user to manually adjust the quantity of spraying, or the quantity of spraying is adjusted in response to the application of the spray when the spray is shipped from a factory, thereby implementing the optimum quantity of spraying.
In a medical inhaler employed for treating or preventing a disease such as asthma, various types of liquid medicines, i.e., spray liquids may be used depending on the state of the disease of the patient. An optimum quantity of spraying is present for the medical inhaler since the patient is choked by spraying and cannot readily inhale the liquid medicine if the quantity of spraying is too large while the time for spraying the liquid medicine is increased to increase the time for treating and restricting the patient if the quantity of spraying is too small. Sprayability varies with the property of the spray liquid, and hence the patient generally has to manually adjust the quantity of spraying to an optimum level in response to the quantity of spraying for each spray liquid or put up with a quantity of spraying larger or smaller than the optimum quantity of spraying when the spray has no function for adjusting the quantity of spraying. When the sprayability of the conventional spray is reduced by abnormality (excessive deterioration, failure or the like) of the apparatus, it takes time for the user to notice the abnormality since the spray has no means for determining the state thereof.
The present invention has been proposed in consideration of the aforementioned problems, and an object thereof is to provide a spray which can automatically adjust the quantity of spraying per unit time to a constant level with respect to spray liquids of various properties, by adjusting power supplied to a spray part so that an interval for feeding a liquid to the spray part is constant. Another object of the present invention is to provide a spray monitoring the state of spraying for immediately posting abnormality of spraying to the user when the abnormality is detected.
The spray according to the present invention comprises a first storage part and a second storage part for storing a spray liquid, a spray part spraying the spray liquid stored in the second storage part, a feeding part feeding a constant quantity of spray liquid from the first storage part to the second storage part, a liquid sensing part detecting presence/absence or increase/decrease of the spray liquid in the second storage part and a feeding determination part for determining whether or not the second storage part requires feeding of the liquid, and adjusts power supplied to the spray part so that the spray liquid is fed to the second storage part at a prescribed interval.
Consequently, the quantity of spray liquid fed to the second storage part per dose can be automatically adjusted to a constant level.
In the spray according to the present invention, utilizing oscillation of an oscillator, a self-excited oscillation circuit utilizing the resonance of the oscillator is formed as a driving circuit for the oscillator, an element such as a coil having a high impedance in an inserted oscillation frequency band is inserted into the side of a GND line in order to separate the oscillator driving circuit and a power supply part from each other, and a circuit rectifying and smoothing an oscillator driving frequency current and converting the current to a voltage is added for monitoring a state of atomization.